Gear-tooth arrangement and transmission incorporating same

ABSTRACT

A bevel-gear or spur-gear transmission arrangement whose two wheels have beds corresponding to conic and cylinder segments, respectively, along their periphery and receive conical and cylindrical roller bodies. The cylindrical roller bodies form part of a chain while the conical roller bodies have apices lying at the intersection point of the shafts of the two wheels.

o Umted States Patent 1 [111 3,748,920

Lambev [4 1 July 31, 1973 [54] GEAR-TOOTH ARRANGEMENT AND 1,333,364 3/1920 Albrook 74/465 TRANSMISSION INCORPORATING SAME 1,159,486 11/1915Froellchm. 74/465 598,629 2/1898 Higgins 74/465 [75] In e tor: YordanGueorguiev Lambev, Sofia. 860,536 7/1907 Ellingham 74/465 Bulgaria2,792,715 5/ 1957 Wojtowicz 74/465 [73] Assignee: DSO Cherna MetalurgiaI Rudobiv,

Sofia Bulgaria Primary Examiner-Leonard H. Gerin [22] Filed: May 24,1971 Attorney-Karl F. Ross [21] Appl. No.: 146,410

[30] Foreign Application Priority Data [57] ABSTRACT May 28, 1970Bulgaria 14803 A bevel-gear or spur-gear transmission arrangement [52]US. Cl. 74/465, 74/417 whose two wheels have beds corresponding to conic[51] Int. Cl. F16h 55/06, Fl6h H20 and cylinder segments, respectively,along their periph- [58] Field of Search 74/464, 465, 417, cry andreceive conical and cylindrical roller bodies. 74/423 The cylindricalroller bodies form part of a chain while the conical roller bodies haveapices lying at the inter- [56] References Cited section point of theshafts of the two wheels.

UNITED STATES PATENTS 3,108,488 10/1963 l-luszar 74/465 2 Claims, 6Drawing Figures Patented July 31, 1973 6 Sheets-Sheet 1 Patented July31, 1973 3,748,920

6 Sheets-Sheet 2 Patented July 31, 1973 6 Sheets-Sheet 3 Patented July31, 1973 6 Sheets-Sheet 4 Fig. 4

Patented Jul 31, 1973 6 Sheets-Sheet 5 Patented July 31, 1973 6Sheets-Sheet 6 Fig.6

GEAR-TOOTH ARRANGEMENT AND TRANSMISSION INCORPORATING SAME Thisinvention relates to a gear-tooth arrangement, which provides acontinuous transmission of motion from one shaft to another without anyslip.

BACKGROUND OF THE INVENTION Various types of gear-tooth arrangements areknown, including involute, cycloidal, lantern and Novikov tootharrangements.

General engineering uses primarily involute tooth arrangements. Thecycloidal and the lantern tooth designs are used mainly in precisionengineering.

In the engineering literature there are many publications dealing withthe geometrical characteristics of gear-tooth designs, the methods forcalculating and designing the tooth profiles, the methods forcalculating and designing the tools for cutting or rolling the teethand, the methods for calculating the measuring instruments and tools forchecking the tooth profile.

The contact strength of the toothed wheels or gears is one of the mostimportant factors influencing their efficiency and determining theresistance of the surface layers of the teeth material against contactdestruction.

Such damage is the main cause for the failure of toothed gears, whichoften have surface hardened teeth and are well lubricated. The analysisof contact damage makes it possible to discern several types ofdestructions, in which one of the basic causes is increasedconcentration of the load along the length and the profile of the tooth.

In the known gear-tooth arrangements, with the exception of the Novikovtooth design, the peripheral' force of the torque is transmitted fromone shaft to the other at the contact lines of the teeth.

Since in most cases the teeth are calculated with regard to bendingstrength, it has been found that the shape of the tooth is not ideal andthe tooth does not possess the required strength properties to providefor the transmission of large forces, while preserving its initialparameters, i.e., the involute and the tooth thickness along the pitchcircle.

The analysis of gear transmissions have shown, that regardless of theprecise methods for the production of the profile of the teeth, duringoperation the tooth profile is changed as a result of the relative slipof the teeth one against the other. The change of the tooth profileleads to serious disturbances in the normal operation toothed-gear driveand its premature failure.

In the Novikov tooth the friction losses are lower than in otherconventional gear toothings, but the production of gears using thisdesign requires a more complicated technology.

OBJECT OF THE INVENTION It is therefore a general object of the presentinvention to provide a gear-tooth arrangement featuring a smoothtransmission of the peripheral force from one shaft to the other bymeans of teeth, which do not contact along a line, but over a surface,so that the tooth profile is not changed even in the case of frictionalcontact.

BRIEF DESCRIPTION OF THE DRAWING For a better understanding of theinvention, reference is made to the accompanying drawing in which thereis illustrated a preferred embodiment of the invention. In the drawings:

FIG. 1 shows the geometry of the gear-tooth arrangement according to theinvention;

FIG. 2 shows in elevation a portion of a cylindrical gear transmissionwith spur teeth partly broken away,

FIG. 3 is a cross-sectional view along line AA of FIG. 2;

FIG. 4 shows a cylindrical-gear transmission with a sleeve-roller-typechain;

FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4 and;

FIG. 6 shows a bevel gear transmission.

SPECIFIC DESCRIPTION As seen in FIG. I, the toothed wheels 1 and 2rotate around their axes 0 and 0 respectively. Located in the toothedwheel 1 with a fixed pitch are the rollers 3, which can rotate aroundtheir axes 0 (0 in FIG. 2). The rollers are attached in such manner,that they remain on the periphery of the toothed wheel 1 in the bedswith a radius r,, corresponding to the radius r of the rollers 3.

When rotating around the axis 0 the rollers 3 on the toothed wheel Iapproach the periphery of wheel 2, which it contacts at one point, andthen the roller 3 rolls in its bed and at the crossing the lineconnecting the axes of rotation 01 and 0,, contacts over a cylindricalsurface the toothed wheels 1 and 2. Next, the rolling of the roller 3takes place in the opposite direction and in the second half of the bedin the toothed wheel 2.

FIGS. 2 and 3 show a cylindrical gear transmission with spur teeth. Inthis case the toothed wheels 1 and 2 rotate around their axes 0 and 0,.Located on the toothed wheel 1 with a fixed pitch are the rollers 3,which can rotate around their axes 0 and rest in beds which have aradius equal to that of the rollers 3. The fixing of the rollers 3 iscarried out by means of both flanges 4, embracing the rollers by theiroutside diameter. The attachment of the flanges 4 to the toothed wheel 1is carried out by means of the clamps 5 and the screws 6. As can be seenin FIG. 1, the wheels have radii of curvature slightly less than thecenter to center distance between them while the beds have centers lyingosculating circles of greater radius.

FIGS. 4 and 5 show a variant type of a cylindrical gear transmissionwith a sleeve-roller-type chain, which comprises the following elements:roller 3, inner flat links of the chain 4, outer flat links of the chainand roller axles with ribs 6.

FIG. 6 shows a bevel gear transmission. Both bevel toothed wheels 1 and2 can be engaged at a different angle. e. Used for the transmission ofthe torque from bevel toothed wheel to the other are the bevel rollers3, located in bevel beds. The fixing of the bevel rollers 3 is carriedout by means of the flanges 4 and 5, attached to the wheel 2 by means ofthe screws 6 and 7. The rollers 3 can be mounted either to wheel 1 or totoothed wheel 2.

The gear transmission, according to the present invention, can also beembodied as a transmission for transforming the rotational motion intostraight-line motion and vice versa, as a gear transmission comprisingtwo cylindrical wheels and a toothed rack.

in another possible variant, one of the toothed wheels 1 or 2 is thedriving wheel, and the rotational motion is transformed in astraight-line motion.

As compared with the known gear transmissions, the gear transmissionaccording to the present invention features the following advantages: ahigher loadcarrying capacity due to the larger contact surface betweenthe teeth of both jointly meshed toothed wheels, and a simplerproduction technology.

The disclosed gear transmission can find application and metallurgicaland heavy engineering, in marine engineering and in other fields ofgeneral engineering. It is particularly suitable for the transmission ofhigh torques at low angular velocities.

What is claimed is:

1. A transmission comprising a first wheel having a periphery formedwith a multiplicity of equispaced cylindrical outwardly concave bedshaving axes lying along a cylinder centered on the axis of said wheeland of a greater radius than that of said wheel; a roller chain having amultiplicity of links extending around the periphery of said wheel andprovided with respective .axles having axes coinciding with those ofsaid beds,

and respective cylindrical rollers rotatable on said axles and seated insaid beds, said rollers having radii equal to the radii of curvature ofsaid beds; and a second wheel having a periphery formed with amultiplicity of equispaced cylindrical outwardly concave beds havingaxes lying along a cylinder centered on the axis of said second wheeland of a greater radius than that of said second wheel, the axes of saidwheels being coplanar, I

said axes of said beds coinciding in the plane of the axes of saidwheels and said beds of said second wheel having the same radii ofcurvature as the rollers and the beds of said first wheel.

2. A bevel-gear transmission comprising a first bevel wheel providedwith a frustoconical periphery centered on the axis of rotation of saidfirst wheel and formed with a multiplicity of equispaced conicaloutwardly concave beds having axes lying along a cone coaxial with theaxis of said first wheel; respective conical rollers received in saidbeds and having axes coinciding with those of said beds, said conicalrollers projecting axially beyond said beds and being of the samecurvature as said beds, said beds having depths less'than the radius ofcurvature thereof; retaining flanges formed on said first wheel andoverhanging ends of said rollers projecting axially beyond said beds;and a second bevel wheel having a frustoconical periphery centered onthe axis thereof, the axis of said wheels being coplanar andintersecting said periphery of said second wheel being formed with amultiplicity of equispaced conical outwardly concave beds having axeslying along a cone coaxial with the axis of said second wheel andadapted to receive said rollers upon rotation of the beds of said secondwheel into the plane of the wheel axes, said beds of said second wheelhaving the same curvature as said rollers and depths less than the radiiof said rollers said rollers and said beds being formed withcomplementary surfaces lying along respective cones having apicescoinciding with the apices of the cones of the bed axes and theintersection point of said wheel axes.

1. A transmission comprising a first wheel having a periphery formed with a multiplicity of equispaced cylindrical outwardly concave beds having axes lying along a cylinder centered on the axis of said wheel and of a greater radius than that of said wheel; a roller chain having a multiplicity of links extending around the periphery of said wheel and provided with respective axles having axes coinciding with those of said beds, and respective cylindrical rollers rotatable on said axles and seated in said beds, said rollers having radii equal to the radii of curvature of said beds; and a second wheel having a periphery formed with a multiplicity of equispaced cylindrical outwardly concave beds having axes lying along a cylinder centered on the axis of said second wheel and of a greater radius than that of said second wheel, the axes of said wheels being coplanar, said axes of said beds coinciding in the plane of the axes of said wheels and said beds of said second wheel having the same radii of curvature as the rollers and the beds of said first wheel.
 2. A bevel-gear transmission comprising a first bevel wheel provided with a frustoconical periphery centered on the axis of rotation of said first wheel and formed with a multiplicity of equispaced conical outwardly concave beds having axes lying along a cone coaxial with the axis of said first wheel; respective conical rollers received in said beds and having axes coinciding with those of said beds, said conical rollers projecting axially beyond said beds and being of the same curvature as said beds, said beds having depths less than the radius of curvature thereof; retaining flanges formed on said first wheel and overhanging ends of said rollers projecting axially beyond said beds; and a second bevel wheel having a frustoconical periphery centered on the axis thereof, the axis of said wheels being coplanar and intersecting said periphery of said second wheel being formed with a multiplicity of equispaced conical outwardly concave beds having axes lying along a cone coaxial with the axis of said second wheel and adapted to receive said rollers upon rotation of the beds of said second wheel into the plane of the wheel axes, said beds of said second wheel having the same curvature as said rollers and depths less than the radii of said rollers said rollers and said beds being formed with complementary surfaces lying along respective cones having apices coinciding with the apices of the cones of the bed axes and the intersection point of said wheel axes. 